Arabic gum, also known as gum Arabic, acacia gum, chaar gund, char goond, or meska, is a natural gum made of hardened sap taken from acacia trees. Arabic gum, which is edible and exhibits glue-like characteristics, essentially consists of a branched long-chain polysaccharide (made up of L-arabinose, D-galactose, L-rhamnose and D-glucuronic acid) and alkaline earth metal and alkali metal salts. Arabic gum is primarily used in the food industry, e.g. as stabilizer, emulsifying or thickening agent, and is an important ingredient, for example, in soft drink syrups and “hard” gummy candies such as gumdrops or marshmallows. Furthermore, it is used as a binder, emulsifying or viscosity increasing agent in pharmaceutical and cosmetic compositions. It is also a key ingredient in traditional lithography and is used in printing, paint production (e.g. as binder in watercolor paint), glue (e.g. on postage stamps, envelopes and cigarette papers), and various industrial applications, including viscosity control in inks and in textile industries. It is an important ingredient in shoe polish and is used as a binder in pyrotechnique compositions.
As a raw material, Arabic gum is available in the form of odorless, brittle, dried sap chunks, which have a colorless to brown appearance. For easy handling and processing, e.g. in the food or pharmaceutical industry, as well as for advantageous storage characteristics, the raw material is generally further processed into powder form.
Although Arabic gum provides excellent properties as emulsifying agent, a drawback is its relatively slow dissolution kinetics in aqueous solvents. Satisfactory dissolution of Arabic gum or compositions containing Arabic gum in aqueous solvents, such as water, may require heating and/or vigorous stirring or shaking over a long period of time, and still, floating undissolved Arabic gum material may be observed. The relatively slow dissolution kinetics of available Arabic gum forms complicates handling and processing of Arabic gum materials. For example, food supplements, such as minerals or organic metal salts, are often provided as ready-to-use powdered dosage forms comprising Arabic gum as matrix material. Such powdered dosage forms are generally dissolved in aqueous solvents, such as in water, and are consumed as beverage. For convenient handling of such compositions, rapid dissolution without the necessity of heating or vigorous agitation is desired, since incomplete dissolution may lead to incomplete uptake of effective agents.
There have been some attempts to modify the properties of Arabic gum, in particular, for enhancing the emulsifying ability of Arabic gum. For example, EP 1 505 078 suggests a heat treatment, wherein Arabic gum is heated to not less than 60° C. in an atmosphere having a relative humidity of 30-100% for modifying the emulsifying properties of Arabic gum. However, said method is not suitable for significantly improving dissolution kinetics of Arabic gum in aqueous solvents.
In the pharmaceutical industry, Arabic gum is, for example, used in the production of nutritional supplements. For example, WO 07/094486 discloses a composition for mediating an improved calcium absorption comprising Arabic gum. Administration of such composition aims at maintaining a balanced level of blood calcium which is essential for cardiac function and prevention of cardiovascular disorders, such as atherosclerosis, coronary artery disease, ischemic heart disease, hyperlipidemia and hypertension. Furthermore, WO 2007/062725 discloses biopolymer-stabilized nanoparticles comprising calcium and optionally Arabic gum as a food product. WO 2004/032901 discloses a pharmaceutical excipient comprising inorganic particles in association with an organic polymeric material which may comprise calcium salts and Arabic gum. The nanoparticles described in WO 2007/062723 and the pharmaceutical excipient described in WO 2004/032901 are manufactured by precipitation and/or controlled crystallization methods, such as by calcium phosphate precipitation. According to WO 2007/062723, the particles described therein exhibit low solubility. WO 2007/065441 describes a granulation process of calcium containing compounds with a water-soluble polymeric substance for obtaining granules which are particularly suitable for the preparation of tablets exhibiting high drug load. However, the dissolution rate of the obtained material is low. Finally, U.S. Pat. No. 5,609,897 describes beverage concentrates comprising calcium, vitamin D, a stabilizing gum such as Arabic gum, and vegetable oil. Arabic gum is used as an emulsion stabilizer in the liquid concentrates. Concentrates in powder form described in U.S. Pat. No. 5,609,897 do not comprise Arabic gum.
The problem of providing a suitable emulsion or solution containing Arabic gum also occurs in other technical fields. For example, the production of paints or inks containing certain pigments, such as pigment black 7 or the like, requires the use of a matrix agent such as Arabic gum for mediating an emulsion of the pigments. However, also in this context, the above mentioned problems concerning the dissolution kinetics of Arabic gum exist.
Therefore, it is an object of the present invention to provide an Arabic gum material exhibiting increased dissolution kinetics, i.e. increased dissolution speed. Thus, it is an object of the invention to provide an easy to handle and readily dissolvable Arabic gum material. Advantageously, said Arabic gum material is particularly suitable for the preparation of beverages. Furthermore, it is an object of the present invention to provide an Arabic gum comprising composition exhibiting improved dissolution kinetics for the components of the composition, such as for organic salts. Furthermore, said Arabic gum material and Arabic gum comprising composition should be producible in an easy and cost saving way.
The object of the invention is solved by the claimed subject-matter.